The compilation worked out of the box on the notebook, but I got the same
error messages as you posted above on my PC @work.

Simply adding these two definitions to glext.h made it compile again,
although I don't know if that was a good idea, or not, so you could try to
add them too and then try to run OpenGL programs in wine and report if that
worked.

I attached my working glext.h to this posting if that helps you (rename it to
glext.h - I'll definetly have to edit the forum permissions a bit to allow uploading
of source code files...)

Alright, I dont' know how to test if OpenGL works in wine. I tried to download
and install some benchmarks as well as an OpenGL demo program, but can't
get them to run because of different error messages.

Could you please try to run your OpenGL application and report if that works
with the modified header file?

I suppose the Wine developers belong to that group of people who think nVidia and ATI are the only producers of video card chipsets.

The problem is, that especially nVidia does a lot for the OpenGL implementation
on Linux and its OpenGL implementation is far the best currently, so it's a
de-facto standard to use the nVidia OpenGL header files. All others have to
include these definitions too as long as there's no real standard.